Frederick w



(No Model.)

F. W. WOHLPERT SEPARABLE SQUARE.

No. 485,402 Patented N0\ 7. 1,-1892.

FlBl 1 FIG I Fuss FIE-34.

INVENTOR:

Fuss ITN ESSESI Attorney.

m: QUERS my. PHO WASHlNOTON n I:

UNITED STATES PATENT OFFICE.

FREDERICK W. WVOHLFERT, OF NEW YORK, N. Y.

SEPARABLE SQUARE.

SPECIFICATION forming part of Letters Patent 5N0. 485,402, datedNovember 1, 1892.

Application filed March 3, 1892.

To all whom it may concern.-

Be it known that I, FREDERICK W. WoHL- FERT, a citizen of the UnitedStates, residing in the city, county, and State of New York, haveinvented certain Improvements in Separable Squares, of which thefollowing is a specification.

My invention relates to metal squares such as are commonly used bycarpenters, masons, and others, and particularly to that class of suchsquares having the two arms or branches made separable, so that thesquares may be more compactly stored or packed for transportation; andthe object of my invention is to provide a lap-joint, whereby the twoarms may be fitted and secured together separably and in a readilydetachable manner, and whereby when so fitted together they will berigid with respect to each other and a fiducial angle at their jointprovided and maintained. Provision is also made for preserving the rigidcharacter of the joint even after the halved and overlapping parts atthe joint have become worn by frequent detachment of the members orbranches.

In the accompanying drawings I have illustrated several forms of myinvention, all, however, containing features in common.

In the drawings, .Figure 1 is a view showing the angle of a squareprovided with my interlocking joint, and Fig. 1 is a section on line 1in Fig.1. Fig. 2 is aview showing the overlapping parts of the membersseparated,

and Figs. 2* and 2 are sections on the respective lines 2 and 2 in Fig.2. Fig. 3 is a view of the securing-screw detached. Fig. 4 is a viewsimilar to Fig. 1, showlng a modified form of the joint in which awedging-.

block and screw are employed in place of the screw seen in Fig. 1; andFig. 4. is a section on line 4 in Fig. 4. Fig. 5 is a View similar toFigs. 1 and 4, showing another modified form of the securing andtightening device; and Fig. 5 is a section on line 5 in Fig. 5.

Referring to the first six figures, A represents one branch or member ofthe square and B the other member. As herein shown, B represents theshorter and narrower member. In such squares these members are joinedtogether firmly at their ends, so that they form a right angle. In thedrawings only the portions of the square about the an- Serial No.423,664. (No model.)

gle are shown; but they may, of course,be of the usual or any length.The metal of the square is quite thin, and it is necessary to the properutility of the square that the members shall be flush with each other onboth faces of the square at the angle, so that no shoulder will appear,hence in making the joint the overlapping parts are halved or gained, sothat when the joint is made one member will lie in the sameplane as theother.

Heretofore the difiiculty has been to provide a joint and fasteningwhich will always hold the members firm and rigid and maintain afiducial angle. I attain this end in the manner I will now describe.

In the member A a recess a is formed, ex-

tending in depth about half-way through the thickness of the same andundercut around its two sides a and its end a Parallel with the sides a,of the recess and about midway end thereof, which is open, and it alsotapers I upward from the bottom of the recess to the top'of the rib, asseen in the cross-sections, Figs. 1 and 2*. At about the center of therecess in the line of the wedge a is a screwhole 0. On the member Bisformed a tenon b, which is beveled at its edges 1) and end b and of suchdimensions as to fit into the recess a by pushing it in endwise, thebevels on its margins engaging the undercut marginsof the recess a. Inthe tenon b is a slit b of such form as to fit over the wedge a when thetenon is pushed into place, and at the proper point in the tenon is acountersunk screw -hole 17 adapted to register with the hole a when thetwo members are fitted together. The tenon b will be normally of thesame dimensions as the recess a; but the wedge a will be a very littlewider than the slit b", whereby when the tenon is pushed into the recessuntil the square shoulder b on the member B abuts snugly against theedge of the member A the wedge will force the two portions of the tenonseparated by the slit against the respective sides of the recess. Whenthe screw 0 is inserted and screwed down into the hole a in the memberA, the head of the screw will force the split tenon down upon the wedgeand also serve to spread it. Of course,being made from metal and theelements being fitted together quite perfectly, the spreading of thetenon by means of the wedge and screw in order to make the jointperfectly firm and tight will be very slight; but it is well understoodthat metal parts may be fitted snugly together and still be free to moveon each other. Such parts may, however, be clamped tightly by a veryslight movement. The screw 0 will serve to tighten up the parts andcause the split tenon to expand into and fit the recess, evenafter theparts have become worn by frequent taking apart and putting together.

In Figs. 4 and 4 another form of the joint is shown. In these views therecess a and tenon b are the same as before described, except that thewedge of and slit b are wedgeshaped only longitudinally and in place ofthe screw 0 a edging-block e is employed, which is secured in place andforced down into the recess by a screw 0. The thicker portion of themember A, adjacent to the recess a, and the tenon b on the member B arerecessed to receive the block 0*. This block has a square or unbeveledshoulder at c, where it engages the recess in the member A, and is alsosquare and fitted loosely at 0 At its edges 0 it is beveled and at itsend 0 it is also beveled, the corresponding walls of the recess beingalso beveled correspondingly. When the tenon has been pushed into therecess, the block e is placed and the screw 0 driven in. The screwpresses the block down, and the bevel at the edge 0 and end 0 will pressthe tenon I) both laterally and endwise simultaneously, thus tighteningit and fixing it rigidly.

Figs. 5 and 5 illustrate another form of the joint, in which the recessa, and tenon b are the same as in Fig. 4; but in lieu of thewedging-block and screw a earn (1, rotatively mounted in a recess in thethicker part of the member A, adjacent to the tenon, is employed. Thiscam 61 takes over the tenon b when in operation, occupying a shallowrecess cl in the tenon and hearing at cl against the wall of said recessin a manner to press the tenon endwise and sidewise into its seat orrecess and to draw its shoulder up firmly to the member A. By turningthe cam around out of the way the tenon maybe drawn out from the recessand the members separated. In Fig. 5 I have also shown the wedge ashortened or abbreviated, but capable of expandng the split tenon at itsextremity.

Having thus described my invention, I claim- 1. A square comprising twomembers A and B, the member A being provided with a recess a, undercutat its sides and end, and a wedge a in said recess, and the member B,provided with a tenon b, beveled at its edges and end, and having a slit12 to engage the Wedge a and means, substantially as described, forsecuring the two members together when the tenon on one occupies therecess in the other.

2. A square comprising two members A and B, the member A being providedwith a recess a, undercut at its sides and end, and a wedge a in saidrecess, which is wedge-shaped or tapered both longitudinally andvertically, the member B being provided with a tenon Z), beveled at itssides and end and having a slit b", which engages the wedge a in therecess when the tenon occupies the recess, and a screw 0 to hold theparts together, said screw being situated in the line of said wedge andslit, substantially as set forth.

3. A square comprising two members A and B, the member A being providedwith an undercut recess a to receive a tenon l) on the other member, themember B, provided with said tenon, which latter is slittedlongitudinally and provided with a countersink in said slit to receive aconical screw-head, and the screw 0, of the form shown, for securing theparts together and expanding said tenon.

In witness whereof I have hereunto signed my name in the presence of twosubscribing witnesses.

FREDERICK V. WOHLFERT.

Witnesses:

HENRY CONNETT, PETER A. Ross.

